The research planned for 1980-81 will follow patterns of 1979-80 but will be based on Blacks instead of Caucasians. We are fortunate in having the assistance of the black track coach at UNLV, Al F. McDaniels, and Bert B. Babero, Professor of Zoology. They are organizing and supervising jogging programs for Blacks during February through April, 1980, and will become members of our research staff thereafter. The detailed program will begin with the aerobic capacity test under the supervision of Terry S. Vitez, M.D. During that test heart rate and blood pressure will be monitored. The desert walks will begin in Boulder City in June and continue through August. From four to six can be completed each day when the temperature reaches 40 degrees C. Each person will complete three walks at a rate designed to require the expenditure of about 40% of aerobic capacity. Major attention will be given to responses of body and skin temperature and heart rate as indicators of effectiveness of thermoregulation. Other observations will include body fat, composition of sweat and sweat rate.